Aims The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning(BEF)experiment in subtropical SE China.Methods Geom...Aims The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning(BEF)experiment in subtropical SE China.Methods Geomorphometric terrain analyses were carried out at a spatial resolution of 5×5 m.Soil samples of different depth increments and data on tree height were collected from a total of 566 plots(667 m2 each).The soils were analyzed for carbon(soil organic carbon[SOC]),nitrogen,acidity,cation exchange capacity(CEC),exchangeable cations and base saturation as soil fertility attributes.All plots were classified into geomorphological units.Analyses of variance and linear regressions were applied to all terrain,soil fertility and tree growth attributes.Important Findings In general,young and shallow soils and relatively small differences in stable soil properties suggest that soil erosion has truncated the soils to a large extent over the whole area of the experiment.This explains the concurrently increasing CEC and SOC stocks downslope,in hollows and in valleys.However,colluvial,carbon-rich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent waterways.The results showed that soil fertility is mainly influenced by topography.Monte-Carlo flow accumulation(MCCA),curvature,slope and aspect significantly affected soil fertility.Furthermore,soil fertility was affected by the different geomorphological positions on the experimental sites with ridge and spur positions showing lower exchangeable base cation contents,especially potassium(K),due to leaching.This geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50 cm depth.Few soil fertility attributes affect tree height after 1-2 years of growth,among which C stocks proved to be most important while pH_(KCl)and CEC only played minor roles.Nevertheless,soil acidity and a high proportion of Al on the exchange complex affe展开更多
Studying the relationship between climate factors and soil organic carbon (SOC) is vitally important. However, how SOC responses to climate (temperature and precipitation) at cohesive extents is poorly studied. Tw...Studying the relationship between climate factors and soil organic carbon (SOC) is vitally important. However, how SOC responses to climate (temperature and precipitation) at cohesive extents is poorly studied. Two transects of approximately the same length (transect P and transect T) were selected to examine the variation of SOC content in relation to mean annual temperature (MAT) and mean annual precipitation (MAP). The coefficients of partial correlation between SOC density and MAT (Rt) and MAP (Rp) were determined to quantify the relationships between SOC density and the two climate factors. The results indicated that for transect T, Rt was statistically significant once the extent level was greater than or equal to two fundamental extent units, while for transect P, Rp showed statistical significance only at extent levels which were greater than two fundamental extent traits. At the same extent levels but in different transects, Rts exhibited no zonal difference, but Rps did once the extent level was greater than two fundamental extent units. Therefore, to study the relationship between SOC density and different climate factors, different minimum extent levels should be ex- amined. The results of this paper could deepen the understanding of the impacts that SOC pool has on terrestrial ecosystem and global carbon cycling.展开更多
The traits of rural domestic sewage emission are unclear,negatively affecting rural domestic sewage treatment and sewage management.This study used data from the Second National Pollution Source Census Bulletin to est...The traits of rural domestic sewage emission are unclear,negatively affecting rural domestic sewage treatment and sewage management.This study used data from the Second National Pollution Source Census Bulletin to establish a data set.The spatial distribution characteristics and main factors influencing rural sewage discharge in the Northern Region were studied using spatial autocorrelation analysis and structural equations.The findings demonstrated that(l)a significant Spearman correlation between drainage water volume(DwV),chemical oxygen demand(COD),ammonia nitrogen(NH_(3)-N),total nitrogen(TN),and total phosphorus(TP)and that the correlation coefficients between DWV and COD,NH,-N,TNand TP were 0.87**,1.0**,0.99**,0.99**,respectively;(2)rural sewage discharge showed spatial autocorrelation,and rural domestic sewage discharge in the districts and counties with an administration was significantly higher than in the surrounding areas;and(3)social development was the main driver rural domestic sewage changes(path coefficient was 0.407**),and the main factors influencing rural domestic sewage discharge were the urbanization rate,years of education,and population age structure.This study obtained the spatial variation law and clarified the main influencing factors of rural domestic sewage to provide data support and a theoretical basis for subsequent rural sewage collection and treatment.Use of the Inner Mongolia Autonomous Region in northern China as a typical case,provides a theoretical foundation for scientific decision-making on rural domestic sewage treatment at the national and regional levels and offers new perspectives for managing pollutants.展开更多
Soil structure degradation in greenhouse vegetable fields reduces vegetable production. Increasing aeration porosity is the key to ameliorating soil structure degradation. Thus, we tested the effect of a porous materi...Soil structure degradation in greenhouse vegetable fields reduces vegetable production. Increasing aeration porosity is the key to ameliorating soil structure degradation. Thus, we tested the effect of a porous material, porous clay ceramic(PLC), on the amelioration of soil structure degradation under greenhouse vegetable production. A 6-month pot experiment was conducted with four PLC application levels based on volume, i.e., 0%(control), 5%(1 P), 10%(2 P), and15%(3 P) using Brassica chinensis as the test plant. At the end of the experiment, soil columns were sampled, and the aeration pore network was reconstructed using X-ray computed tomography(CT). The degree of anisotropy(DA), fractal dimension(FD), connectivity, aeration porosity, pores distribution, and shape of soil aeration pores and plant biomass were determined. The DA, FD, and connectivity did not significantly differ as the PLC application rate increased.Nonetheless, aeration porosity significantly linearly increased. The efficiency of PLC at enhancing soil aeration porosity was 0.18% per Mg ha^(-1). The increase in aeration porosity was mainly due to the increase in pores > 2 000 μm, which was characterized by irregular pores. Changes in aeration porosity enhanced the production of B. chinensis. The efficiency of PLC at increasing the plant fresh weight was 0.60%, 3.06%, and 2.12% per 1% application rate of PLC for the 1 P, 2 P, and 3 P treatments, respectively. These results indicated that PLC is a highly efficient soil amendment that improves soil structure degradation by improving soil aeration under greenhouse conditions. Based on vegetable biomass, a 10% application rate of PLC was recommended.展开更多
铅基压电陶瓷因其优异的压电性能,被广泛应用于压电器件。其中,压电驱动器要求压电陶瓷具有较高压电性能并且在电场下具有较高的电致应变和较小的应变滞后。本研究通过施主-受主共掺,得到高压电性能和低电场应变滞后的PZT陶瓷。采用传...铅基压电陶瓷因其优异的压电性能,被广泛应用于压电器件。其中,压电驱动器要求压电陶瓷具有较高压电性能并且在电场下具有较高的电致应变和较小的应变滞后。本研究通过施主-受主共掺,得到高压电性能和低电场应变滞后的PZT陶瓷。采用传统固相反应法制备了(1-x)(Pb_(0.95)Sr_(0.05))(Zr_(53)Ti_(47))O_(3)-x BiAlO_(3)+0.2%MnO_(2)陶瓷(掺杂量为质量百分数),并对其微观结构和压电性能进行了研究。结果表明:BiAlO_(3)掺杂量较少时,陶瓷中缺陷偶极子的“钉扎”效应使得陶瓷畴壁转动困难,陶瓷压电性能较弱,应变滞后也较小。随BiAlO_(3)掺杂量增加,缺陷偶极子“钉扎”效应减弱,陶瓷的压电性能和应变滞后随之提高。本实验得到的性能最优组分为x=1.75%,该组份陶瓷的压电系数d_(33)=504 p C/N,机电耦合系数k_(p)=0.71,机械品质因数Q_(m)=281,居里温度T_(C)=312℃,在10k V/cm电场下的应变滞后仅为15%,并且还具有较好的温度稳定性,是一种具有应用价值的压电驱动器用压电陶瓷材料。展开更多
基金funded by the German Research Foundation(DFG FOR 891/1,2 and 3)funds from the National Natural Science Foundation of China(NSFC 30710103907,30930005,31170457 and 31210103910)+2 种基金the Swiss National Science Foundation(SNSF)financed by the Sino-German Centre for Research Promotion in Beijing(GZ 524,592,698,699 and 785)the University of Tübingen,Germany(PROMOS).
文摘Aims The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning(BEF)experiment in subtropical SE China.Methods Geomorphometric terrain analyses were carried out at a spatial resolution of 5×5 m.Soil samples of different depth increments and data on tree height were collected from a total of 566 plots(667 m2 each).The soils were analyzed for carbon(soil organic carbon[SOC]),nitrogen,acidity,cation exchange capacity(CEC),exchangeable cations and base saturation as soil fertility attributes.All plots were classified into geomorphological units.Analyses of variance and linear regressions were applied to all terrain,soil fertility and tree growth attributes.Important Findings In general,young and shallow soils and relatively small differences in stable soil properties suggest that soil erosion has truncated the soils to a large extent over the whole area of the experiment.This explains the concurrently increasing CEC and SOC stocks downslope,in hollows and in valleys.However,colluvial,carbon-rich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent waterways.The results showed that soil fertility is mainly influenced by topography.Monte-Carlo flow accumulation(MCCA),curvature,slope and aspect significantly affected soil fertility.Furthermore,soil fertility was affected by the different geomorphological positions on the experimental sites with ridge and spur positions showing lower exchangeable base cation contents,especially potassium(K),due to leaching.This geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50 cm depth.Few soil fertility attributes affect tree height after 1-2 years of growth,among which C stocks proved to be most important while pH_(KCl)and CEC only played minor roles.Nevertheless,soil acidity and a high proportion of Al on the exchange complex affe
基金Under the auspices of Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues of Chinese Academy of Sciences(No.XDA05050503)National Key Technology Research and Development Program of China(No.2013BAD11B00)National Natural Science Foundation of China(No.41301242)
文摘Studying the relationship between climate factors and soil organic carbon (SOC) is vitally important. However, how SOC responses to climate (temperature and precipitation) at cohesive extents is poorly studied. Two transects of approximately the same length (transect P and transect T) were selected to examine the variation of SOC content in relation to mean annual temperature (MAT) and mean annual precipitation (MAP). The coefficients of partial correlation between SOC density and MAT (Rt) and MAP (Rp) were determined to quantify the relationships between SOC density and the two climate factors. The results indicated that for transect T, Rt was statistically significant once the extent level was greater than or equal to two fundamental extent units, while for transect P, Rp showed statistical significance only at extent levels which were greater than two fundamental extent traits. At the same extent levels but in different transects, Rts exhibited no zonal difference, but Rps did once the extent level was greater than two fundamental extent units. Therefore, to study the relationship between SOC density and different climate factors, different minimum extent levels should be ex- amined. The results of this paper could deepen the understanding of the impacts that SOC pool has on terrestrial ecosystem and global carbon cycling.
基金This work was supported by the National Natural Science Foundation of China(No.51838013)the project of Inner Mongolia"Prairie Talents"Engineering Innovation Entrepreneurship Talent Team,and the Innovation Team of the Inner Mongolia academy of Science and Technology(No.CXTD2023-01-016).
文摘The traits of rural domestic sewage emission are unclear,negatively affecting rural domestic sewage treatment and sewage management.This study used data from the Second National Pollution Source Census Bulletin to establish a data set.The spatial distribution characteristics and main factors influencing rural sewage discharge in the Northern Region were studied using spatial autocorrelation analysis and structural equations.The findings demonstrated that(l)a significant Spearman correlation between drainage water volume(DwV),chemical oxygen demand(COD),ammonia nitrogen(NH_(3)-N),total nitrogen(TN),and total phosphorus(TP)and that the correlation coefficients between DWV and COD,NH,-N,TNand TP were 0.87**,1.0**,0.99**,0.99**,respectively;(2)rural sewage discharge showed spatial autocorrelation,and rural domestic sewage discharge in the districts and counties with an administration was significantly higher than in the surrounding areas;and(3)social development was the main driver rural domestic sewage changes(path coefficient was 0.407**),and the main factors influencing rural domestic sewage discharge were the urbanization rate,years of education,and population age structure.This study obtained the spatial variation law and clarified the main influencing factors of rural domestic sewage to provide data support and a theoretical basis for subsequent rural sewage collection and treatment.Use of the Inner Mongolia Autonomous Region in northern China as a typical case,provides a theoretical foundation for scientific decision-making on rural domestic sewage treatment at the national and regional levels and offers new perspectives for managing pollutants.
基金supported by the National Natural Science Foundation of China (Nos.41571209 and 41401240)the 135 Plan and Frontier Fields Program of the Institute of Soil Science,Chinese Academy of Sciences (No.ISSASIP1627)the Technology Project of Hongta Tobacco Group Company Limited,China (No.HT2016-6221)。
文摘Soil structure degradation in greenhouse vegetable fields reduces vegetable production. Increasing aeration porosity is the key to ameliorating soil structure degradation. Thus, we tested the effect of a porous material, porous clay ceramic(PLC), on the amelioration of soil structure degradation under greenhouse vegetable production. A 6-month pot experiment was conducted with four PLC application levels based on volume, i.e., 0%(control), 5%(1 P), 10%(2 P), and15%(3 P) using Brassica chinensis as the test plant. At the end of the experiment, soil columns were sampled, and the aeration pore network was reconstructed using X-ray computed tomography(CT). The degree of anisotropy(DA), fractal dimension(FD), connectivity, aeration porosity, pores distribution, and shape of soil aeration pores and plant biomass were determined. The DA, FD, and connectivity did not significantly differ as the PLC application rate increased.Nonetheless, aeration porosity significantly linearly increased. The efficiency of PLC at enhancing soil aeration porosity was 0.18% per Mg ha^(-1). The increase in aeration porosity was mainly due to the increase in pores > 2 000 μm, which was characterized by irregular pores. Changes in aeration porosity enhanced the production of B. chinensis. The efficiency of PLC at increasing the plant fresh weight was 0.60%, 3.06%, and 2.12% per 1% application rate of PLC for the 1 P, 2 P, and 3 P treatments, respectively. These results indicated that PLC is a highly efficient soil amendment that improves soil structure degradation by improving soil aeration under greenhouse conditions. Based on vegetable biomass, a 10% application rate of PLC was recommended.
基金National Natural Science Foundation of China(51831010)National Key R&D Program(2021YFA0716502,2021YFB3800604)。
文摘铅基压电陶瓷因其优异的压电性能,被广泛应用于压电器件。其中,压电驱动器要求压电陶瓷具有较高压电性能并且在电场下具有较高的电致应变和较小的应变滞后。本研究通过施主-受主共掺,得到高压电性能和低电场应变滞后的PZT陶瓷。采用传统固相反应法制备了(1-x)(Pb_(0.95)Sr_(0.05))(Zr_(53)Ti_(47))O_(3)-x BiAlO_(3)+0.2%MnO_(2)陶瓷(掺杂量为质量百分数),并对其微观结构和压电性能进行了研究。结果表明:BiAlO_(3)掺杂量较少时,陶瓷中缺陷偶极子的“钉扎”效应使得陶瓷畴壁转动困难,陶瓷压电性能较弱,应变滞后也较小。随BiAlO_(3)掺杂量增加,缺陷偶极子“钉扎”效应减弱,陶瓷的压电性能和应变滞后随之提高。本实验得到的性能最优组分为x=1.75%,该组份陶瓷的压电系数d_(33)=504 p C/N,机电耦合系数k_(p)=0.71,机械品质因数Q_(m)=281,居里温度T_(C)=312℃,在10k V/cm电场下的应变滞后仅为15%,并且还具有较好的温度稳定性,是一种具有应用价值的压电驱动器用压电陶瓷材料。